超声辅助氨水提取-ICP-MS法测定矿物质预混料中总碘

试验建立了电感耦合等离子体质谱(ICP-MS)测定矿物质预混料中碘元素的方法,优化了氨水浓度及超声时间等因素对提取的影响,并探讨了提取液的稳定性。结果表明,在超声40 min条件下, 20%氨水溶液可较好地提取矿物质预混料中的总碘,碘可稳定存在于提取液48 h;以103Rh作为在线内标,采用4 mL/min氦气碰撞池模式的ICP-MS法测定碘含量,碘的线性范围为0～200μg/L,线性相关系数R为0.999 8,方法检出限为0.015 mg/kg。对预混料样品加入低、中、高三个梯度标物测定,回收率在95%～105%之间,重复性RSD为2.6%,再现性RSD为1.4%, n=7。该方法准确、便捷、回收率良好,适用于不同矿物质预混料中总碘含量的测定。     

电感耦合等离子体质谱法同时测定牛奶及其制品中26种有害元素含量

目的建立电感耦合等离子体质谱法(inductively coupled plasma-mass spectrometry,ICP-MS)同时测定牛奶及其制品中26种有害元素含量的分析方法。方法样品经过压力罐消解技术消化后采用电感耦合等离子体质谱法结合内标元素法,分别测定纯牛奶、酸奶、奶粉等3种奶制品中26种元素的含量。结果在0～50μg/L线性范围内,26种元素的线性关系良好(r~20.999);方法平均加标回收率为86.8%～114%,各元素相对标准偏差均小于10.0%(n=6);方法检出限为4.2×10~(-6)～4.4×10~(-3) mg/kg。结论该方法前处理简便易行,精密度高、灵敏度高,准确快速,适用于牛奶及其制品中的有害元素测定。     

碱提取-电感耦合等离子体质谱法测定食品中的碘

目的 建立碱提取-电感耦合等离子体质谱法测定食品中碘含量。方法 样品经5% 四甲基氢氧化铵(TMAH)溶液于85 ℃±5 ℃提取3小时,离心后取上清液上机,以铼作为内标,经电感耦合等离子体质谱仪测定。结果 在0.5～50 μg/L的线性范围内,回归方程呈现良好的线性关系,r=0.9997。该方法检出限为0.003 mg/kg,定量限为0.01 mg/kg,回收率为94%～102%之间,RSD小于10%。结论 该方法操作简单,灵敏度高,适用于食品中碘含量的测定。     

微波消解-电感耦合等离子体质谱法测定蔬菜中硒含量

目的建立微波消解-电感耦合等离子体质谱法测定蔬菜中硒含量的方法。方法样品经微波消解后,不经盐酸还原,直接采用电感耦合等离子体质谱仪测定。结果本法测定样品的RSD为4.4%(n=6),检出限为0.08μg/L,在0~200μg/L范围内线性关系良好,相关系数为0.9999,回收率在92%~103%之间,优于国标方法,质控样品测定值均在标准参考值范围内。结论本法操作简便,线性范围宽泛,结果准确可靠,可用于蔬菜中硒含量的测定。     

湿法消解-电感耦合等离子体发射光谱法测定保健食品中7种常见矿物质元素

目的建立湿法消解-电感耦合等离子体发射光谱法测定保健食品中铜、锰、铁、锌、钙、镁、钾7种常见矿物质元素的含量。方法使用高氯酸含量较高的硝酸-高氯酸体系湿法消解样品,彻底消解保健食品中难以消解的植物油、甘油、乙二醇、二氧化钛等化合物,使用电感耦合等离子体发射光谱法配备更节省氩气的微型炬管上机测定样品。结果在一定质量浓度范围内, 7种元素线性关系良好,相关系数大于0.999,检出限为0.2~10mg/kg,定量限为0.6~30mg/kg,加标回收率在92.1%~104.7%,相对标准偏差小于3.89%。结论本方法前处理消解样品完全、物理化学干扰少、结果准确可靠,具有良好的精密度和回收率,适用于保健食品中7种常见矿物质元素的准确检测。     

液相色谱-电感耦合等离子体质谱法测定饲料中的六价铬

目的建立液相色谱-电感耦合等离子体质谱法(liquid chromatography-inductively coupled plasma mass spectrometry,LC-ICP-MS)测定饲料中六价铬含量的分析方法。方法以碱性溶液和磷酸缓冲液为提取溶剂,100 mmol/L硝酸铵溶液(pH值7.5)为流动相,采用Dionex IonPac AG19(4 mm×50 mm,4μm)+Dionex IonPac AS19阴离子柱(4 mm×250 mm,4μm)对样品提取液进行分离,电感耦合等离子体质谱进行测定。结果该方法检出限为0.30 mg/kg,线性相关系数大于0.999,精密度RSD5%,回收率在80%～110%之间。结论该方法科学准确、操作简单快速,可满足各种饲料中六价铬含量的测定。     

微波消解-电感耦合等离子体质谱法测定话梅中的铅

目的 建立微波消解-电感耦合等离子体质谱法(inductively coupled plasma mass spectrometry, ICP-MS)测定话梅中铅的分析方法。方法 话梅样品用硝酸-过氧化氢经微波消解仪消解, 定容后用电感耦合等离子体质谱仪测定, 用185Re内标校正铅含量, 并转换成样品中的铅含量。结果 铅含量在0~50 μg/L线性关系良好, 线性相关系数r=1.0000, 检出限为0.0314 mg/kg。在精密度实验中, 其相对标准偏差为0.35%~2.15%, 在1.0 mg/kg的添加水平下, 加标回收率为94.42%~102.36%。结论 该方法线性关系好, 检出限低, 稳定性好, 回收率高, 测定结果准确, 适合话梅中铅的测定。     

电感耦合等离子体质谱法测定锑的含量

通过采用电感耦合等离子体质谱法测定样品中锑的浓度含量,建立了一整套检验方法,包括预处理和结果分析。方法检出限(n=11,k=3)为0.09μg/L,精密度(n=7)为2.03%,回收率为95%～102%,线性良好,相关系数大于0.999。方法准确、可靠、快速,适用于日常检测。     

ICP-OES法测定婴幼儿配方奶粉中钼的方法研究

建立电感耦合等离子体发射光谱法测定婴幼儿配方奶粉中的钼含量。此方法用微波消解法处理婴幼儿配方奶粉样品,然后运用电感耦合等离子体发射光谱法分析样品,同时探讨最佳消解奶粉样品和分析样品的条件。微波消解-电感耦合等离子体光谱法测定婴幼儿配方奶粉中的钼,方法在0~0.500 mg/L范围内线性关系良好(0.999 9),检出限可以达到0.048 mg/kg,6次奶粉样品测定结果的相对标准偏差小于3%;在加标量为0.2、1.0、2.0 mg/kg 3种梯度浓度下,回收率在96.6%~102%之间;标准参考物质的分析结果也在证书值范围内。该方法使用试剂少,空白值低,具有良好的精密度和准确度,适用于婴幼儿配方奶粉中钼的测定。     

电感耦合等离子体质谱法测定植物性农产品中碘含量

目的建立了电感耦合等离子体质谱法(inductivelycoupled plasma-mass spectrometry,ICP-MS)测定植物性农产品中碘含量。方法样品中加入碳酸钾和硫酸锌,采用干灰化法破坏有机物,固定样品中的碘,利用电感耦合等离子体质谱仪在标准模式和碰撞模式下测定植物性农产品中碘的含量。结果碘标准溶液在1.0~15.0μg/L质量浓度范围内线性关系良好,标准模式和碰撞模式下相关系数(r)分别为0.9999和0.9998。不同基质样品在3个不同添加水平下的回收率在86.9%~103.1%之间,相对标准偏差在0.88%~3.06%之间,符合要求。2种测定模式下的方法检出限一致,红薯为0.005 mg/kg、西红柿和豇豆为0.003 mg/kg。测定的国家有证标准物质(GBW 10020和GBW 10023)中碘的含量,测定值均在标准值不确定度范围内。结论与传统的硫氰酸铁-亚硝酸催化动力学法相比,该方法操作简便、节省试剂、稳定性好、精密度高、检出限低,大大提高了检测效率,适用于植物性农产品中碘含量的快速、准确定量分析。     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Textural Properties of Cold-set Gels Induced from Heat-denatured Whey Protein Isolates

A 9% whey protein (WP) isolate solution at pH 7.0 was heat-denatured at 80°C for 30 min. Size-exclusion HPLC showed that native WP formed soluble aggregates after heat-treatment. Additions of CaCl2 (10–40 mM), NaCl (50–400 mM) or glucono-delta-lactone (GDL, 0.4–2.0%, w/v) or hydrolysis by a protease from Bacillus licheniformis caused gelation of the denatured solution at 45°C. Textural parameters, hardness, adhesiveness, and cohesiveness of the gels so formed changed markedly with concentration of added salts or pH by added GDL. Maximum gel hardness occurred at 200 mM NaCl or pH 4.7. Increasing CaCl2 concentration continuously increased gel hardness. Generally, GDL-induced gels were harder than salt-induced gels, and much harder than the protease-induced gel.     

Occurrence of bisphenol-F-diglycidyl ether (BFDGE) in fish canned in oil

The levels of bisphenol-F-diglycidyl ether (BFDGE) were quantified as part of a European survey on the migration of residues of epoxy resins into oil from canned fish. The contents of BFDGE in cans, lids and fish collected from all 15 Member States of the European Union and Switzerland were analysed in 382 samples. Cans and lids were separately extracted with acetonitrile. The extraction from fish was carried out with hexane followed by re-extraction with acetonitrile. The analysis was performed by reverse phase HPL C with fluorescence detection. BFDGE could be detected in 12% of the fish, 24% of the cans and 18% of the lids. Only 3% of the fish contained BFDGE in concentrations considerably above 1mg/kg. In addition to the presented data, a comparison was made with the levels of BADGE (bisphenol-A-diglycidyl ether)analysed in the same products in the context of a previous study.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Contribution of European research to risk analysis

The European Commission's, Quality of Life Research Programme, Key Action 1—Health, Food & Nutrition is mission-oriented and aims, amongst other things, at providing a healthy, safe and high-quality food supply leading to reinforced consumer confidence in the safety of European food. Its objectives also include the enhancing of the competitiveness of the European food supply. Key Action 1 is currently supporting a number of different types of European collaborative projects in the area of risk analysis. The objectives of these projects range from the development and validation of prevention strategies including the reduction of consumers risks; development and validation of new modelling approaches; harmonization of risk assessment principles, methodologies, and terminology; standardization of methods and systems used for the safety evaluation of transgenic food; providing of tools for the evaluation of human viral contamination of shellfish and quality control; new methodologies for assessing the potential of unintended effects of genetically modified (genetically modified) foods; development of a risk assessment model for Cryptosporidium parvum related to the food and water industries; to the development of a communication platform for genetically modified organism, producers, retailers, regulatory authorities and consumer groups to improve safety assessment procedures, risk management strategies and risk communication; development and validation of new methods for safety testing of transgenic food; evaluation of the safety and efficacy of iron supplementation in pregnant women; evaluation of the potential cancer-preventing activity of pro- and pre-biotic ('synbiotic') combinations in human volunteers. An overview of these projects is presented here.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the